The RADIUS (Remote Authentication Dial-In User Service) protocol is widely used as a telecommunications standard protocol for the purposes of an AAA (Authentication, Authorization and Accounting) system. Among other uses, the protocol is used for performing mobile subscriber authentication for mobile Internet services, authorization verification and accounting information management. In operation, the RADIUS protocol uses a UDP (User Datagram Protocol) with a transport layer and conforms to a request/response scheme based on a client-server structure.
When employing the RADIUS protocol, some Internet Service Providers require end users to be authenticated by using the Media Access Control (MAC) address. Alternatively, Internet Service Providers may require end users to be authenticated by a UserName.
Using the standard RADIUS protocol as the primary authentication, end users can be authenticated only on MAC or alternatively on a UserName attribute, but cannot use both in the same authentication policy.